1. Field of the Invention
The present general inventive concept relates to an image forming apparatus and a control method thereof, and more particularly to an image forming apparatus including a discharge unit to discharge printed papers successively and promptly and a control method thereof.
2. Description of the Related Art
Generally, an image forming apparatus, such as a printer, a copying machine, a fax machine, or a multi-function printer, includes a paper feeding unit, a print unit, and a paper discharge unit. The paper feeding unit supplies paper to the print unit, the print unit prints images on the supplied paper, and the paper discharge unit discharges the printed paper outside.
A conventional image forming apparatus is classified as a front-input-front-out (FIFO) type or a front-input-side-out (FISO) type according to a paper feeding direction and a paper discharging direction.
The FIFO type image forming apparatus is configured such that the paper is supplied from the front and discharged to the front. The paper discharge unit of the FIFO type image forming apparatus includes a first discharge roller which feeds the printed paper to the rear from the print unit disposed at the front portion of the image forming apparatus, a reverse roller which reverses the moving direction of the paper fed by the first discharge roller from the rear to the front, and a second discharge roller which discharges the printed paper, whose moving direction is reversed, outside.
However, in the conventional image forming apparatus having the above described paper discharge unit, the reverse roller rotates in a forward direction and in a reverse direction sequentially to completely discharge one sheet of printed paper outside. Therefore, when discharging the printed papers successively, the following sheet of printed paper to be discharged should stand by until the preceding sheet of printed paper completely leaves the reverse roller.
So as to successively discharge the preceding sheet of printed paper and the following sheet of printed paper without interference, the interval between two papers should be long. Accordingly, in order to prevent a decrease of the overall paper discharging speed (a print speed), the rotational velocity in the reverse direction of the reverse roller is set to be faster by 2˜3 times more than the rotational velocity in the forward direction. However, in driving the reverse roller as described above, an operational noise of a driving motor increases. Further, a developing device of the print unit idles for a long span, and it results in toner stress and/or abrasion of a photosensitive drum. Accordingly, a lifespan of components reduces, and thus maintenance costs increase.